Stoker



Nov. 15, 1938. F". T. NlcH-LSON STOKER Filed April 3. 1937 2Sheets-Sheet 1 Nov. l5, 1938. Fr. NlcHoLsoN 2,136,594

` sToKER Filed April s, 1937 2 sheets-snaai z Jfys` Patented Nov. 15, Ye

omeosm'rss PATENTomos ,h t gppiiosti: s, 134,895

"Ihe, present invention lrelates to stokers ;for the expanding` passageof the throator connecmechanically feeding coal into` furnaces, andtion. l l j` e more particularlyuto the means for;` supplying Otherfeatures` of the `invention Will `appeal e the coal to the Stoker. t o,1, inthe appendedrawingsand the followingjde- Asi commonly constructed,these stokers are scription'wherein are shown and describeda pre-` 5arranged with a plurality or series of coal feedferred `form ofthepresent invention as applied ing units to `which the 4coal is supplied`from a to an underfeed mechanical ,Stoker of a well single commonsourceysuch as atbinor hopper, known type# i i Y i c'onnectionsibeing`providedirom the bottom fof; .,Intheaeempyin drawings Fig. 1 1S 8i Vel'-the hopper to eachistoker unit. Commonly `these tical side sectional"view taken on line I-e-I of 10 i binscr hoppers` are provided withdownwardly F1352 of onlythose portions o; such a` stoker iconvergingside and bottom malls, and theconf `1,115,tlJlfttiOnlaster@dm'edneSSay 101" @n1111- nections or throatst also have converging wallsderstanding of the Present" irivfntQIl, FIEQQZ iS e whichformscontraoting passage ionthe cosi; a front view 'of the `same.partlyin elevation 11n such` constructions difhcuity isl oftenr ext and partlyin Seotioa:` F1a:-` ie a topview, partly 15 perienced in n securingwanunlnterrupted movee iniseetiompenlne 31--3` 0f Fig.` ZLEE- 4 1Sali/'ere ment or now ofthe coal through such acon; l tioalaideSeotionaiview, onanenlarsed seale.of trsoting throat, `duetothetemitmcyof` the cosi the upper ,portion ofthe onneetion lor throat,to pack and arch over under the weight` of the showing` the iagitatorifor ,i the coal; Elgs. 5, 6

zo coeiandthe wedging action offithe'taperingside yand '7, are atopplan, a front, and a s1de'e1e 2o wallswwhllestoppageof thecoal supplyoccurs vatiori, respeotivelvtof the -new and improved evenowhen the coalis dry, itis much more likethroat member separate and"detachedefro1n the1y where the coal is wetor damp;` and since it is Dtliernparti Fig. 8 isa side `elevatioiri of a modii a 'common practiceito construct thesecoal suped 10mi Qf the Saillie Dart; aIidFg? 91Sa UMIS- ply bins orhoppers in theopen with no roof verse sectionalview, on an enlargedscale, of one 25 or other sheitenthe cociis exposed toiirsin and of; theeross-iiemiqers of thexeoal agitator; snow. I i .f l ,e Thestoker,"which isishown only inpart inthe l iti isv the object` ofthepresent invention to drawings; comprises bfiyi Series 0f Stoker eprovide: a construction in which such stopping units extending acrossthe front of the furnace,

3o 'in the movement .of the -ooai from `the hopper each unithavias acylinder with a ram therein 3o to the stoker will be avoided andracontinuous, and a common aetuatine'shaftfoi reciprocating uninterruptedsupplyvoi` coal to each Stoker unit thE Tam t0 feed the al 111mm@furnaces! An willbe insuredp 1 i l i ,z elevated binor hopper extendingacross thefront To the above Vends thepresent invention con- 0f thefill'llaf With` Si Connection 0f ,thlat from 35 templates the provisionof a connection `or throat the bottom 0f the hOPPeI t0 B ah ram Wunder35 `betiiveen the hopper or `other source of supplyand Supplies the C031'thereto' e e i e the Stoker units inwhich an expanding passage.Refrriing stt9, thQse 9011510115 0f the On' forthe coalis provided sothatl the compacting structmll trei drawntgl `Whim mi: ,01d of thecoalby the wedging' action' of the walls -a'ndfve @ma ,n hg Bfr dselclqmpr e a' "40 `ofthe throat will be prevented" and"all danger pluralty m" sie .e-S of @In cy m ers mounted 40 i A e i y e each opposite anopening I3 in the furnace wall i ofarchingflminated N {5,1Eachgcylinderis formed with an opening @other milie oiflth? invention 1Sith? W0' i1 in Aits top won odjocentthe furnace, Vthe side vision of aconnection 0r threat membefof the nousitheineextenties` upwardly on@overging e PbQVe WDG which is adapted t9 be posmod as shown in Fig.` 2f.The coalis supplied tothe 45 or inserted `in the converging throats oi'installacylinder through he Opening |V1-and then fed tions` alreadyConstructed and thereby eliminate by the reciprooatious for the `rain(notshownp, liability of interference in theifuturewith the through thepassageylgintq the furnace; Aram regular supply of coal tothe stokenshaft I9 mounted across the `front ofthe-cylinl i Still anotherfeatureof; the present invention ders is `rotated slowly from `a`suitable source of 50 e is theprovision of Ya `stirring ,device oragitator power to impaiftthe Ieedingand return strokes i`adjacenttheupper or entrance end ci the coal fto the rants of theseveralunitsmf suitable con- `passage in the connection or throat, withsit- Anections ffamiliar tofythose `sllllled l in the `art, *ableactuating mechanism fto facilitate and` lnwhichit is not necessaryhereto describe. e

sure the passage of e. coal from thesupplyinto i: 'IA'heoal `for theyseveral units of"`the`stcker is `cui supplied from a hopper or bin 2|having the downwardly converging front and rear walls Il and Il andextending across the face of the furnace above the stoker units. Inthese prior constructions the connections or throats and theopeningsintheramcylinderswereprovidedwith asubstantiallyverticalbackwall Il and down-y wardly inclined and converging front andside walls Il and Il, respectively. all four wallsnttingintotheopeningil in the topofthe ram cylinder.asshowninliga 1and2.l

'llo provide access to the interior of the conntionorthroattoloosenthecoalincaseitsdownward movement should beprevented by arching orforanyotherreason, an opening Il wasformed nearthe bottom of the front wail Il for a slide or closure 8l removably heldin place rbythe lipsv or ears I1 on the wall. When the coal becamepacked or arched over and ceased to flow. the slide would be removed anda poker or suitable implement used to free and loosen the coal.

l Inorder to eliminate this contracting passage orthroat with itsliability to cause packing and arching of the. coal, the connectionmember described above has been provided. in accordance with the presentinvention, with an expanding throat or passage so that all compactingand wedging of the coal at this point is prevented;

This is accomplished. in the embodiment illus# trated in the drawing. bytheprovision of an additional or supplementary throat' member adapted tobe positioned ln the old converging throat. and provided with anexpanding passage for the coal. None of the old parts'already installedhave to bedisturbed, the new'throat member being of such a. size andshape asl to fit within' the old throat andbe retained in positionvbyits own weight and the weight of the coal above without requiring theuse of bolts or lother fastening devices. 1

The preferred e form of throat member constructed in accordance with thepresent invention is shown detached in Figs. 5, 6 and '7, and installedin position in Figs.) to 4. It comprises a rectangular flat top 4l of aslze'tojflt within the entrance opening of the oldthroat, with marginalportions of the top resting uponthe curved connecting tops 4I ofthe oldside walls of adjacent throats, (see Fig. 2) 'Ihe top of the new throatmember is provided with an opening or recess Il of rectangularconnguratlon extending inwardly from the rear edge ofthe top. 4Extendingdownwardly from the bottom face of the top at the edges of the opening.are the front wall I1 and the side walls 0, each of which divergesoutwardly from the vertical center line of the opening. so that athree-sided expanding passage is formed having a greater cross-sectionalarea at its bottom than st ,the top. Triangular supports or webs Ilmutually reinforce and strengthen the top and side walls.

The bottom margins ofthe side walls are bevelled slightly, as shown atvI3, to avoid contact with the lowerends ofthe 'side walls of the oldthroat and with the upper portions of the expanding side walls of thecylinder, which might interfere withthe proper seating of the top Il onthe tops of the old throat walls; vThe front wall of the supplementarythroat is vprovided at its bottom with the opening or recess Il, theinner lower corners. of thewall being bevelled, as at I'L'to avoidcontact with the ram when the latter is reciprocated in ithej cylinder.Oneach sideoi' the recess Il are positioned lips or ears Il which areundercut on their inner faces adiacent the wall to receive a closure orgate Il to close the opening 55. This gate or closure comes opposite theold closure 35 on the original throat construction so thatif for anyreason it is desired to gain access to the interior of the ram cylinderor to the ram therein, this can be done by removing first the outerclosure in the old throat and then the inner closure on thesupplementary throat.

Preferably the new and improved supplementary throat or connectionwillbe cast in one piece. While all the intermediate throat members willbe identical, separate and slightly different castings would be requiredfor the end sections where one side wall of the old throat was straight,as shown in Fig. 2.y For such locations the margin at the top would beof reduced width on one side or the other, as required.

`While the three-wall construction shown in Figs. 5 to 'I has been foundmost satisfactory in actual use, the fourth or back wall qi the coalpassage being formed by the straight back wall of the old throat, it maybe preferred in some locations to use a throat member having four wallscompletely enclosing the coal passage, with all of the walls divergi'ng.Such construction is shownin Fig. 8.

To insure the continuous flow of coal from the hopper into the upper endof the coal passage in the new throat construction, there has beenprovided a stirrer or agitator for the coal immediately above theentrance opening, the agitator being actuated from some convenientsource of power.' preferably the ram shaft. A convenient form ofagitator is illustrated in Figs. l to 4 of the drawings, and comprisesan elongated grid or ladder-like Vconstruction which rests upon thealigned tops of the throat members and is slowly reciprocatedlongitudinally during the operation of the stolzer.

' As shown in Fig. 3, the agitator-comprises the elongated side members05 and 61 extending the width of the hopper and connected by the spacedtransverse or cross-members 69. A convenient form of assembly is bywelding the cross-members to the side members which are arranged as bestshown in Fig. 4, with the front member positioned flatwise and the rearmember edgewise. Shorter intermediate transverse members 1| which extendonly part way across from the front side member toward the rear memberare welded to the front member only. Preferable the transverse membersare of segmental form in cross section, as shown on an enlarged scale inFig. 9, the bottom face being fiat and the top face arcuately convex. f

The agitator is reciprocated in the illustrated embodiment oftheinvention from the continuously rotating ram shaft I9 by the crank 13mounted on the end thereof, as shown in Fig. 3. The rotary movement ofthe crank is transferred into reciprocatory motion of the agitator bymeans of a vertical shaft 18 mounted to oscillate in suitable bearingsupport 11. Fixed to its lower end is the arm 19 connected by the linkor pitman 8| to the crank 13, while at its upper end ls secured the arm83 connected by link 8B to the agitator. 'I'hus as the ram shaftrotates, the agitator is reclprocated back and forth over the topsurfaces of the throat members', stirring and loosening the adjacentcoal so that a continuous movement oi' the loose coal into the entranceend of the passage in the throat members is insured.

The convex upper surface of the transverse members tends to maintain theagitator in posiaisasai tionfupon the top surface of the throat members,irrespectiveof `the direction of movement, but to` avoid anypossibilityV of therear memberof the agitator rising, thehold-downguides l! have `been provided, `(see Figs; 2 and 4),`which are welded inposition `to the back wail atthe top of the oldthroats orconnections.

The extent of movement oil the agitator is preferably such that thecross-members'` l! will traverse substantially the entire distancebetween adjacent throat openingabut not pass over any part of theopenings themselves, while the shorter intermediate members 1i willtraverse substantially that portion of the top surface of the throatmembers lying to the front of the opening. Thus,

on each cycle-of operation or double stroke of the agitator,substantially the entire fiat iop surface of eachv throat member will betraversed,` but at no time will the entrance to the passage in thethroat member be obstructed or covered by any part of the agitator.

In the operation of the stoker illustrated in the drawings, the coalfeeds downwardly in a continuous, slowly moving stream from the hopperor bin through the expanding passages of the throat members into the ramcylinders. As the ram shaft rotates slowly, increments of coal are fedsuccessively from the cylinders into the fm'- nace by the reciprocationsof the rams. At the same time, the agitator is moved back and forthadjacent the entrances to the passages of the throat members,maintaining the coal in loose and free condition irrespective of whetherit is wet or dry, or what the height or weight of the coal may be in thehopper.

While the present invention has been shown and described as embodied ina construction wherein a separate and detached throat member is firstformed and then positioned within the old connection or throat of aninstallation, the invention in its broader aspects is not to belimitedthereto, as it contemplates the provision in the coal supplyingmeans `for a stoker of connections having expanding passages fordelivering coal to the stoker whereby packing and arching over ofthecoal with resultant interruption in its movement will be avoided. A i

Nor is the present invention limited to the specific form andarrangement of the `various parts as herein illustrated and described,as these may be varied as the occasion `and conditions require withinthe scope of the language of the appended claims.

\ Having thus described the invention, what is claimed is: i

1. The combination with a hopper for supplying coal to a stoker or thelike, connections between the hopper and the stoker having convergv ing,downwardly extending passages, and supplementary devices positioned insaid passages, said devicesfeach having a downwardly expanding coalconveying-passage to facilitate the movement of coal from `the hopper tothe Stoker.

2*. A throat member adapted to be positioned in the downwardlyconverging throat of a stoker coal supply, said member comprising a topwith an opening therethrough and a plurality of diverging, downwardlyextending walls forming an expending passage for the coal with adischarge opening not materially less in cross-sectional area than saidthroat.

3. A throat member adapted to be positioned in the downwardly convergingthroat of fuel supply means of a stoker, said member having a lpassagetherethrough for delivering coal from said means` `fitting within thedischarge end of said throat.

i 4. A throat" member adapted to be positioned within the downwardlyconverging walls of the fuel supply means of a Stoker,` said membercomprising a substantially fiat top with an opening therethrough, wallsextending downwardlyfrom the top at `the opening and diverging to forman expanding passage for the coal, said diverging walls of the throatmember terminating adjacent the termination of the walls of the fuelAsupply means.

5. A throat member adapted to be positioned within the downwardlyconverging walls of the fuel supply means of a stoker, said membercomprising a substantially flat top with an opening therethrough at oneedge, walls extending downwardly from the top at the edges of theopening and diverging to form with one oi' the walls of the fuel Isupplymeans an expanding passage for the coal.

6. A throat member adapted to be positioned `in the fuel supplying meansfor a Stoker, said member comprising a fiat top having a rectangularopening therein of substantially less area than the top, side wallsextending downwardly from the top adjacent the opening to form an ex-`panding downward passage, one of said walls being provided with anopening in the lower portion thereof, and a removable closure therefor.7. A hopper for supplying coal to a plurality of stoker units or thelike, said hopper having a substantially flat bottom with a plurality ofspaced openings therethrough, connections from the openings havingdownwardly expanding passages for the delivery of coal from the hopperto the stoker units, an agitator in the hopper comprising a plurality oflongitudinal members, coal agitating cross-members adjacent the flat`bottom of the hopper and spacedfrom one another between the openings,and means adapted to be driven from the Stoker for actuating theagitator to cause the cross-members to reciprofree and unobstructed atall times.

8. A hopper for supplying coal to a plurality of stoker units or thelike, said hopper having a substantially fiat bottom with a plurality ofspaced openings therethrough, connections from the openings havingdownwardly expanding passages for the delivery of coal from the hopperto the stoker units, an agitator in the hopper comprising longitudinalmembers on opposite sides of the hopper and adjacent the bottom thereof,coal agitating cross-members connected at their ends to saidlongitudinal members and spaced from one another between the openings,shorter agitating members intermediate the cross-members connected toone of said longitudinal members and terminating short of the openings,and means for actuating the agitator to move the cross-members betweenthe openings.

. 9. The combination with a stoker for feeding coal to a furnacecomprising a ram cylinder with a coal receiving opening in the upperwall thereof and diverging side walls extending upwardly from saidopening, of a hopper having downwardly converging side walls connectingwith said cylinder walls, and a throat member positioned between saidhopper walls with a top extending across the hopper and with an openingthrough the top, and side walls surrounding the downwardly to form adischarge throat, of a supplementary throat member positioned in thethroat of the hopper, said member having a top extending across thethroat oi' the hopper, an inlet opening through the top, and downwardlydiverging side walls terminating in a, discharge opening positionedwithin and approximately of the same cross-sectional area as the throatoi the hopper.

' FRANK T. NICHOLSON.

